he Red-eared Slider is a subspecies of the
Pond Slider (Trachemys scripta) which is
found in northern Mexico and much of the
eastern USA. The common name is derived from
the distinctive red stripes on the side of the head,
coupled with the turtles’ habit of sliding quickly from
basking spots into water if disturbed. Red-eared
Sliders are native to the Mississippi drainage
system, from southeast Colorado to Virginia and
Florida, south to northern Mexico. They are
immediately recognisable due to the unique red
stripes on their heads, in addition to which the head,
legs and tail are covered with conspicuous creamy-
yellow lines. They prefer slow-moving or still water
and are often to be found basking in numbers on
exposed rocks or logs. Although omnivorous, they
consume large amounts of aquatic vegetation.
Females are usually larger than males, and
maximum carapace length is around 40cm, although
most adult specimens are significantly smaller;
sexual maturity may be attained with a carapace
length of just 10-15cm. The Red-eared Slider has
become the most popular turtle in the global pet
trade, and has been exported around the world. It
has subsequently established naturalised
populations in all continents except Antarctica and is
ranked among the world’s 100 most invasive
species, which is ironic considering it is struggling
somewhat in its natural range. The Teenage Mutant
Ninja Turtles were identified in a comic book as
being Red-eared Sliders, and predictably this only
served to enhance the species’ popularity as pets.
In Europe, Red-eared Sliders have already
demonstrated their ability to displace native species,
and importation has been banned by the European
Union. In Australia, fears are heightened by the fact
that they attain sexual maturity earlier than native
species of freshwater turtles, plus they have higher
fecundity and are generally larger in size. Retained
sperm may allow a female to produce fertile eggs a
year after mating. Although the possible impact of
Red-eared Sliders in Australian environments is at
present almost wholly speculative, they may also
transmit a blood parasite, in addition to damaging
local ecosystems through predation and destruction
of aquatic plants and the nests of waterbirds through
their habit of basking on these structures. Red-eared
Sliders are also known to carry Salmonella bacteria
(although so are many other reptiles), and there are
concerns that drinking water could be contaminated,
and that handling could also result in salmonellosis.
But do we really need to be worried? Are there
already naturalised breeding populations of
Red-eared Sliders in Australia? And if so, where
have they come from? The last question is the
easiest to answer as, like the rest of the world (and
the Corn Snakes found around Sydney), Red-eared
Sliders encountered in the wild in Australia are
believed to have originated from (illegally-held) pets.
In fact, naturalised Red-eared Sliders have been
found in Western Australia, the Australian Capital